A 47-year-old Massachusetts woman claims that her son, Michael Duggan, is the father of Caylee Anthony, the murder victim in the Casey Anthony trial.

Casey Anthony, who is facing first-degree murder charges in the death of her 2-year-old daughter Caylee, has never revealed the name of the toddler's father.

Donna MacLean recently told investigative reporter Diane Diamond on The Daily Beast website that she is "100 percent certain" she is the biological grandmother of Caylee and her late son Michael is the father.

Michael Patrick Duggan died in 2007 in a one-car accident in Falmouth, Massachusetts. Before he died, MacLean said that he told her that he had a daughter with a woman named Casey in Florida.

"I asked him about the circumstances… who is the family? He said the parents were George and Cindy Anthony. I asked who she was and he said her name is Casey. He told me her dad was a cop and I said, ‘Oh, Mike! Does she want child support?'" MacLean recalled.

Duggan was working for a moving company in Tennessee at the time that Caylee was conceived, according to MacLean. He would often visit Orlando to visit friends.